During a typical web-browsing session, pages containing hypertext-markup language (HTML) code are provided to a user's browser by one or more web servers. Such pages normally contain HTML code pointing to an image file, which causes that image file to be displayed within the user's browser. The existing file type and size of an image file is not always appropriate for all users and all situations. For example, a user having a visual disability might be better suited to see larger images in his or her browser, while a user of a mobile device might be better suited to see smaller images in his or her browser. Additionally, when an image file is updated, there are typically a number of portions of HTML code that are updated to reflect the identity of the updated image file, which code updates are made each time that the image file is updated. Further, there is a need to provide security capabilities to discourage the copying of proprietary image files and provide a way to authenticate the source of an image file. Conventional browsing and image-delivery methods fail to address the foregoing problems.